var iNum1=1;
var fNum2=2.5;
var sName='pan';
var bIsOk=true;
// JavaScript有六中类型：string/number/boolean/undifined/null/object
console.log(typeof(bIsOk));

var score=90;
if(score<60){
    console.log('不及格')
}else if(score<=70){
    console.log('刚及格')
}else if(score<=80){
    console.log('一般般')
}else{
    console.log('优秀')
}